Turbine-nozzle diaphragm



. A 1,641,665 Sept. 6,1927. AlDEVAUD A TURBINE NozzLE D'IAH'RAGM Filed Nov. 2l, '1925 Inventor Albert J. vDew/cls cl Patented Sept. 6, Y1927.

f FFICE.

ALBERT J. DEVA'UD, 0F SCHENECTADY, NEW YORK, ASSGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATON GE' NEVI YORK. i

TURBINE-QZZLE DIAPHRAGIVI.

Application led November In the manufacture of elastic fluid turbines, it is customary to split the casing and diaphragme in the plane of the axis of 'the machine, and since nozzle partitions extend angularly, this means that the partitions crossing the plane of the split are cut in two.

The cutting in two of these partitions weakens them, particularly their forward or discharge ends, and in the case of diaphragn'is having nozzle partitions of considerable radial length it has been found necessary to provide struts or braces for the discharge ends of the split partitions to give additional strength to them.

In connection with the operation of certain turbine bucket wheels, vibrations occurred which could not be attributed to any known causes.' ln the particular instances, the wheels had been tested in accordance with the methods set forth in the patents to Campbell, Numbers 1,502,903 and l,502,904

dated July 29, 1924 and they should have been entirely free from vibration Vat the normal operating speeds. However, such was not the case.

After careful investigation, l discovered that in the particular instances, the vibrations were due to the disturbances set up in the elastic Huid flow by the above-referred to struts or partitions. The buckets when passing through the regions of disturbed flow were subjected to a slight shock or impulse, and in the particular instances the periods were such as to be effective in producing and maintaining vibrations.

To overcome the above trouble, l found it necessary to omit entirely the struts or braces for the cut nozzle partitions, and in order to be enabled to do this and still havethe required nozzle partition strength, l now split the diaphragm along lines between nozzle partitions rather than on lines through the nozzle partitions.y By this means I avoid altogether any cut nozzlev partitions. Preferably l split the diaphragm along straight angular linesrrather than on curved lines as this makes machining of the parts easier. j v

In the drawing, ig. l is a perspective view of a turbine nozzle diaphragm embodying myl invention, the two halves of the diaphragm being shown separated; Fig. 2 is a face view showing the halves of the dia- 21, 1925. Serial No. 70,625.

phragm together, andFig. 3 is adetail view of the edge of the diaphragm. n l

Referring to thev drawing, l indicates the upper halfV of a turbine nozzle diaphragm,

2 the lower half, and 3 the nozzle partitions. The halves of vthe-diaphrapnn arey held in alignment by keys l which fit into keyways 5 and by` suitable fasteners 6. The nozzle partitions directly adjacent to the horizontal plane through the center ofthe diaphragm are indicated at 7 and 8 and as will be clear from the drawing, the line of parting between the two halves of the diaphragm runs between these nozzle partitions. As shown the line of parting is in twoangular planes 9 and 10 which lie entirely between lt-he adj arent nozzle partitions 7 and 8.

By my invention I avoid cut nozzle, partitions and hence am enabled to do away entirely with braces or struts between any of the nozzle partitions. Asa result, the elastic fluidV flow from the entire ring of nozzles is even and uniform and hence is not likelyto be a means vof causing vibrations.

`What l claim as new and desire to secure by Letters Patent of the United States, is:

l. A split nozzle diaphragm having a 'continuous ring of angularly-extending nozzle partitions which overlap one another, charf acterized by the fact that the split extends along lines between adjacent nozzle partitions whereby the cutting of any nozzle partition' is avoided. f

2. A split nozzle diaphragm having a continuous ring of angularly-extending nozzle partitions which overlap one another, characterized by the fact that the split extends along pla-nes which are at an angle to each other and which lie between adjacent nozzle partitions whereby the cutting of anynozzle partition is avoided.

3. A split nozzle diaphragm having concentric radially spaced portions connected solely by a continuous ring of' angularlyextending duplicate-nozzle partitions which overlap one another, characterized by thev fact that the split extends along lines between adjacent nozzle partitions whereby the cutting of any Vnozzzle partition is avoided. ln witness whereof, I have hereunto set my hand this 20th day of November, 1925.V

ALBERT J. DEVAUD. 

